Filling element for filling containers with a liquid product, filling machine and method for filling containers

ABSTRACT

The invention relates to a filling element for filling systems for filling bottles or similar containers with a liquid filling product, comprising a liquid channel for the liquid product in a housing of the filling element, which forms at least one discharge opening for introducing the liquid product into the respective container, and with valve means for the controlled discharging of the liquid product into the respective container.

The invention relates to a filling element according to the preamble of patent claim 1, to a filling machine according to the preamble of patent claim 9 and a method for filling bottles or similar containers according to the preamble of patent claim 12.

Filling elements for use in filling machines, in particular in rotary filling machines in which a plurality of filling positions are each formed on the periphery of a rotor that can be driven to rotate about a vertical machine axis, and with each filling position consisting of a filling element with an associated container carrier, are known in different embodiments. For the controlled delivery of the liquid product into the respective container, the filling elements exhibit at least one liquid valve with a valve body which can be moved by an actuating device between only two positions, namely between an open and a closed position. In isolated cases, liquid valves having an appropriately configured actuating device also provide three possible switching states of the liquid valve, namely the closed and fully open states and an additional partially open state.

Pneumatic or electromagnetic operating elements which move the valve body of the liquid valve between the individual switching positions at high speed serve to switch the particular liquid valve or valve body concerned. One disadvantage of this is that during the said switching, very sudden and pulse-like changes occur in the volumetric flow rate of the product to be filled, leading to pressure pulses and hence very often to an undesirable frothing of the liquid product, with a consequential deterioration in the filling throughput (filled containers per unit of time) of the filling machine.

Methods are also known in which the filling machine is controlled according to saved or stored container-specific filling curves which represent the filling height in a container as a function of the volume of liquid product already filled into the container. In this method it is not the filling speed that is controlled or regulated but the relative motion between the bottom of a long filling tube and the particular container type so as to prevent an unwanted excessive immersion of the filling tube in the product.

It is the object of the present invention to provide a filling element which avoids these disadvantages and which in particular also makes it possible, at a high throughput of a filling machine (high number of filled containers per unit of time), to achieve a filling characteristic that is optimally adapted to the type of container and/or product and that is defined for example by a container-specific and/or product-specific filling curve.

The filling speed (volumetric flow rate of product per unit of time) of the inventive filling element can be adjusted and varied at will, such adjustment and variation being continuous or infinitely variable or essentially infinitely variable. The change in the volumetric flow rate is effected for example by an infinitely variable or essentially infinitely variable change of the effective orifice cross-section of the at least one liquid valve and/or of a return gas valve disposed in a return gas path of the filling element, i.e. by an infinitely variable or essentially infinitely variable lift of a valve body of the liquid valve or of the return gas valve.

For the purpose of the invention, ‘infinitely variable’ or ‘essentially infinitely variable’ means primarily and preferentially ‘infinitely variable’ in the strict sense, but also means a variation or adjustment in very small adjustment or variation increments, with the number of adjustment or variation increments that are possible between the two extremes ‘closed’ and ‘open’ being greater than ten and with each adjustment or variation increment causing a change in the effective flow cross-section of the opened liquid valve or of the opened return gas valve which is not more than 10% of the orifice cross-section of the fully open liquid valve or return gas valve.

In the present invention, the infinitely variable adjustment or variation of the liquid valve and/or of the at least one return gas valve is effected by an electrically, pneumatically or hydraulically triggerable actuating element which is for example a piezo motion element/motion actuator or other electric, hydraulic or pneumatic linear drive.

The inventive filling element permits filling methods which avoid sudden changes in the volumetric flow rate of the filled product and consequential pressure pulses as well as an unwanted frothing of the product resulting therefrom. It is in particular possible to dynamically adapt the filling speed to properties of the container or product, for example to the form and/or contour of the containers used, and also to the momentary contours or cross-sectional area or product surface area of the interior of the container concerned, said contours or areas constantly changing as the product is filled, and/or to the frothing tendency or to the CO₂ concentration in the product or to other product parameters, so that even when a filling machine is operating at a high throughput, the frothing of the product and the associated oxygen uptake in the product is at least minimised.

The product speed is controlled or regulated preferentially according to an optimised container-specific and/or product-specific filling curve which sets the filling speed as a function of time. The inventive embodiment permits filling methods with optimal accelerations and/or decelerations of the product for necessary changes in filling speed, and in particular permits an infinitely variable adaptation of the volumetric flow of the product to areas of the product surface that are continuously or discontinuously changing as the already filled product volume changes.

The filling method can in particular be configured with a slow initial filling at a moderately increasing filling speed to cover the container base with product, with a gentle transition to maximum filling speed in the straight section of the particular container, with a gentle, preferentially infinitely variable reduction and/or adjustment of the filling speed in container regions of varying cross-section, and with a gentle transition to a slow filling phase so as to precisely achieve the required filling height or filling quantity as the case may be.

Further embodiments, advantages and possible applications of the invention arise out of the following description of embodiments and out of the figures. All of the described and/or pictorially represented attributes whether alone or in any desired combination are fundamentally the subject matter of the invention independently of their synopsis in the claims or a retroactive application thereof. The content of the claims is also made an integral part of the description.

The invention is explained in detail below through the use of embodiment examples with reference to the figures. In the figures:

FIG. 1 shows a schematic view in cross-section of a filling element of a filling system according to the invention;

FIG. 2 shows a container-specific or bottle-specific filling curve;

FIG. 3 shows a schematic view in cross-section of a filling element of a filling system according to the invention in another embodiment;

FIG. 4 shows an enlarged partial view of the filling element of a filling system according to the invention in the region of a piezo actuator;

FIG. 5 shows a schematic view in cross-section of a filling element of a filling system according to a further embodiment of the invention.

FIG. 1 shows a filling element 1 of a filling machine, for example a rotary filling machine, which on the periphery of a rotor 3 that can be driven to rotate about a vertical machine axis, exhibits a plurality of filling elements 1 of the same type for the open-jet filling of containers or of bottles 2 with a liquid product. With each filling element 1 is associated a container carrier 4 which together with filling element 1 forms a filling position 5 and at which the respective bottle 2 is held suspended from a mouth flange 2.2 formed beneath bottle mouth 2.1 and at a distance from the underside of the filling element and/or at a distance from a local delivery orifice 6.

Filling element 1 has a housing 7 with a liquid channel 8 into which an element 9 serving as a gas seal is inserted on the underside of filling element 1 to form delivery orifice 6, and which in its upper region is connected by line 10 incorporating flow meter 11 to a tank 12 of the filling system or of the filling machine. While tank 12 is provided for all filling elements 1 or filling positions 5 of the filling machine collectively, each filling element 1 is connected to tank 12 by its own dedicated line 10 and own flow meter 11.

A liquid valve 13 is provided in liquid channel 8 for the controlled delivery of the product flowing to the respective bottle 2 as an open jet 14 during the filling process. Liquid valve 13 consists essentially of a valve body 13.1 which interacts with a valve seat formed by the inside face of liquid channel 8 and which can be moved up and down on a vertical filling element axis FA inter alia to open and close liquid valve 13. Operation is effected by a pneumatic actuating device 15 which consists essentially of a cylinder 16 provided at the top of housing 7, and a piston 17 with piston rod 18 whose lower end facing away from piston 17 is connected to valve body 13.1. Actuating device 15 and valve body 13.1 are preloaded in an open position of liquid valve 13 by a compression spring 19 surrounding piston rod 18.

Above piston 17 and inside cylinder 16 is formed a cylinder space 20 to which the pressure of a gaseous and/or vaporous fluid such as compressed air for example can be applied in a controlled manner for moving piston 17 against the force of compression spring 19 and hence for moving valve body 13 to the closed position in the way described in greater detail below. At its lower end, filling element 1 is further configured with an auxiliary space or ring space 21 which encloses delivery orifice 6 and which is connected by a channel 22 on the filling element side to a ring channel 23 provided on rotor 3 for all filling elements 1 of the filling system in common, said connection being for a CIP cleaning of filling elements 1 and filling machine, for example.

Cylinder space 20 is connected by an electrically triggered control and regulating valve to a source 26 for the pressurised gaseous or vaporous fluid. An electrical triggering stage or driver stage 25, which is in turn triggered by an electronic controller 27, serves the triggering of control and regulating valve 24.

The particularity of the filling system shown in FIG. 1 is that, unlike in the case of known filling systems, valve body 13.1 is movable by actuating device 15 not only between a fully closed and a fully open state of liquid valve 13 but that by appropriate control of the pressure in cylinder space 20, the volumetric flow rate of the product flowing to the respective bottle 2 can be controlled continuously or between a value of nil (closed state of liquid valve 13) and a maximum value (fully open state of liquid valve 13). As a result it is in particular possible, even with open-jet filling, to configure the control of the respective filling process and/or of the volumetric flow rate or of the filling speed, i.e. the amount of product that is fed to a particular bottle per unit of time, according to a profile (filling curve) as indicated by curve 28 in FIG. 2 and which, while taking into consideration the bottle type—i.e. the shape and/or size of bottle 2 in particular—the momentary fill level, the product and other filling parameters, represents the optimum characteristic of filling speed V over time t, applying the various different curve sections 28.1-28.5 that correspond to the following part-phases of the filling phase concerned:

Curve section 28.1 Start of filling with gentle increase of filling speed V by slow continuous or infinitely variable opening of liquid valve 13;

Curve section 28.2 Rapid filling at constant or maximum constant filling speed V and with fully open liquid valve 13;

Curve section 28.3 Gentle reduction of the filling speed to a reduced filling speed V by increasingly slow closing of liquid valve 13;

Curve section 28.4 Final filling at constant or essentially constant yet reduced filling speed V;

Curve section 28.5 Gentle completion of the filling phase by slow closing of liquid valve 13.

The respective control and regulating valve 24 and hence liquid valve 13 as well are controlled by electronic controller 27 as a function of the measured signal from flow meter 11 and of the bottle-specific or container-specific filling curve 28 which is stored in a working memory of electronic controller 27 and imported from a database of the machine controller into the working memory, for example prior to the filling of bottles 2 of a certain bottle type.

In a schematic similar to FIG. 1, FIG. 3 shows a filling element 1 a for the pressurised filling of containers in the form of bottles 2 with the liquid product, wherein during filling, the respective bottle 2 that is here again suspended from container carrier 4 is held with its bottle mouth 2.1 in sealed position up against filling element 1 a in the region of delivery 6. The filling system forms part of a filling machine, for example of a rotary filling machine, in which a plurality of filling elements 1 a is provided on rotor 3 that can be driven to rotate about the vertical machine axis.

In housing 7 of filling element 1 a is configured liquid channel 8 which exhibits delivery orifice 6 and which is connected, via line 10 that is provided individually for each filling element 1 a and that incorporates flow meter 11, to tank 12 which is provided on rotor 3 for all filling elements 1 a collectively.

For the pressurised filling of bottles 2, the interior of tank 12 is partially filled with the liquid product, thereby creating a liquid space 12.1 that is occupied by the product and forming above liquid space 12.1 a gas space 12.2 that is filled with a compressed inert gas such as for example CO₂.

In liquid channel 6 is provided liquid valve 13 a that is formed essentially by valve body 13 a.1 which interacts with a valve surface formed by the inside surface of liquid channel 8 and which an actuating device 15 a can move on filling element axis FA inter alia between a position that fully closes liquid valve 13 a and a position that fully opens said liquid valve. Valve body 13 a.1 is provided on a return gas tube 29 that serves as a valve stem and that is moved axially on filling element axis FA in a controlled manner by actuating device 15 a.

Inside housing 7 there are configured a plurality of gas paths generally indicated in FIG. 3 by 30 and having control valves 31 and 32 by which a chamber 33 connected to the upper end of return gas tube 29 can be connected in a controlled manner to ring channels 34 and 35 that are provided for all filling elements 1 a on rotor 3 a collectively. Ring channel 34 is connected to gas space 12.2 of tank 12 and serves in particular to preload bottle 2 with inert gas from gas space 12.2 when filling a bottle 2, i.e. at the beginning of the filling phase concerned. Ring channel 35 serves inter alia to take away the inert gas which is forced out of the bottle by the inflowing product during pressurised filling and which flows into ring channel 35 via return gas channel 29 and control valve 32 acting as a return gas valve.

By controlling the opening and closing of control valve 32 (return gas valve), the filling speed, i.e. the amount of product that flows per unit of time to bottle 2 during the filling phase, can be controlled or regulated. To this end, control valve 32 is configured so that as well as having a fully open and a fully closed state it is infinitely variably adjustable between these two extreme states in regard to the effective orifice cross-section and therefore in regard to the volumetric flow rate. By appropriate triggering of control valve 32 it is therefore possible to control or regulate the filling speed as a function, for example, of the optimised bottle-specific or container-specific filling curve 28.

Control valve 32 is in turn pneumatically triggerable. For this purpose, a cylinder space 36 of an actuating element of control valve 32 is connected via a control and regulating valve 24 a.1 with source 26 that supplies the compressed gaseous or vaporous fluid, for example compressed air.

In filling element 1 a, liquid valve 13 a is furthermore configured so that it permits an infinitely variable controlling or regulating of the volumetric flow rate between its open and closed states, here again by an appropriate adjustment or variation of the orifice cross-section of partially open liquid valve 13 a. To this end, the pneumatically operable actuating device 15 a consists of a ring piston 37 that can be displaced axially, i.e. on filling element axis FA, in a cylinder space of housing 7; ring piston 37 is provided on return gas tube 29 and together with return gas tube 29 is preloaded in a position that opens liquid valve 13 a by compression spring 38 surrounding return gas tube 29. On its side facing away from compression spring 38, ring piston 37 confines a cylinder space 39 to which a control and regulating valve 24 a.2 can apply the pressure of pressure source 26 in a controlled manner. The two control valves 24 a.1 and 24 a.2 are in turn triggered by electronic controller 27 via control or driver stages 25 a.1 and 25 a.2 respectively and as a function inter alia of the signal of flow meter 11 and of a container-specific or bottle-specific filling curve stored e.g. in the working memory of electronic controller 27, for example as a function of filling curve 28 in FIG. 2.

In this respect, control valve 32 and liquid valve 13 a that is controlled by actuating device 15 a are in turn parts, for example, of a closed control loop in which the measured signal supplied by flow meter 11 is compared as an actual value with a given actual value [sic] represented for example by the filling curve, with an adjustment of the setting of control valve 32 and/or of liquid valve 13 a being made according to appropriate control or regulating criteria, e.g. such that liquid valve 13 executes a rough setting or adjustment of the filling speed and return gas valve 32 executes a fine correction of the filling speed, or vice versa.

It is of course also fundamentally possible to configure control valve 32 or liquid valve 13 a in such a way that this valve can only assume an open or a closed state, while the infinitely variable or continuous control and regulation of the filling speed during the respective filling phase, e.g. according to container-specific or bottle-specific filling curve 28, is effected by triggering liquid valve 13 or control valve 32.

When control valve 32 is configured solely for opening and closing, then this return gas valve or control valve serves for example to define the maximum filling speed in the open state and the reduced filling speed in the closed state, with liquid valve 13 a being appropriately triggered so as to produce the gentle and/or moderate increase in filling speed according for example to curve section 28.1 and the gentle decrease in filling speed according for example to curve sections 28.3 and 28.5.

FIG. 4 shows a simplified partial view in cross-section of a filling element 1 b which is part of a filling system for the open-jet filling of containers or bottles 2 and which only differs from filling element 1 in that between the piston rod of actuating element 15 and valve body 13.1 of liquid valve 13 b, there is provided an electrically triggerable actuating element 40, for example in the form of a piezo actuator. The actuating element is triggerable by a driver stage 42 of electronic controller 27 specifically to execute an infinitely variable translatory motion, i.e. a motion of valve body 13.1 on filling element axis FA as a function of the triggering, and such that as well as the pure opening and closing motion attainable with actuating element 15, a controlling or regulating of the filling speed during the respective filling phase is also possible, here again for example based on a container-dependent or bottle-dependent filling curve 28 that is optimum for bottles 2. Actuating element 15 is configured and/or triggered only for opening and closing liquid valve 13 b.

FIG. 5 shows a filling element 1 c that is part of a filling system for the pressurised filling of bottles 2. Essentially, filling element 1 c only differs from filling element 1 b in that actuating element 15 c, which is equivalent in function to actuating element 15 a, is only configured for opening and closing liquid valve 13 c, which corresponds to liquid valve 13 a, whereas the filling speed is controlled or regulated by a return gas valve 32 c which corresponds to control valve or return gas valve 32, said return gas valve 32 c having an electrically triggerable actuator 43, e.g. in the form of a piezo actuator, which is directly triggered by electronic controller 27. It is as a function of this triggering that the volumetric flow rate of the return gas through return gas valve 32 c, and hence also the filling speed during pressurised filling, are infinitely variably controllable.

The invention has been described hereinbefore by reference to different embodiments. It goes without saying that numerous variations as well as modifications are possible without departing from the concept underlying the invention. Common to all embodiments is that during the respective filling phase the filling speed can be controlled or regulated infinitely variably, preferentially as a function of a container-specific or bottle-specific filling curve optimised for the particular containers that are used, and preferentially in consideration of inter alia the container shape or contour and again preferentially in consideration of the product volume already filled into the container concerned and as a function of the particular product or corresponding product parameters. The infinitely variable control or regulation of the filling speed is achieved by an appropriate setting or regulating of the opening state or orifice cross-section of liquid valve 13, 13 a-13 c and/or at least of one return gas valve 32, 32 c.

REFERENCE LIST

1,1 a-1 c Filling element

2 Bottle

2.1 Bottle mouth

2.2 Mouth flange

3 Motor

4 Container carrier

5 Filling position

6 Delivery opening

7 Housing

8 Liquid channel

9 Gas seal

10 Line

11 Flow meter, for example a MID flow meter

12 Tank

12.1 Liquid space

12.2 Gas space

13, 13 a-13 c Liquid valve

13.1 Valve body

14 Free jet

15,15 a-15 c Actuating element

16 Cylinder

17 Piston

18 Piston rod

19 Compression spring

20 Cylinder space

21 Ring space

22 Channel

23 Ring channel

24, 24 a.1, 24 a.2 Control and regulating valve

25 Driver stage

26 Source for pressurised fluid

27 Control element

28 Filling curve

28.1 -28.5 Curve section

29 Return gas tube

30 Gas path

31 Control or clamping valve [sic]

32,32 c Return gas valve

33 Chamber

34,35 Ring chamber

36 Cylinder space

37 Piston

38 Compression spring

39 Cylinder space

41 Actuating element

42 Driver stage

43 Actuator

FA Filling element axis 

1-15. (canceled)
 16. An apparatus for filling containers with a liquid product, said apparatus comprising a filling element, said filling element having a housing, a liquid channel for channeling said liquid product, said liquid channel forming part of a delivery orifice for passing said liquid product into a container, and a valve assembly for controlled delivery of said liquid product into a container, said valve assembly being configured for infinitely variable control or regulation of filling speed during a filling phase, said filling speed being defined by an amount of liquid product flowing into said container per unit of time.
 17. The apparatus of claim 16, wherein said valve assembly is provided in said liquid channel, and wherein said liquid valve has a cross-section that is infinitely variable for controlling or regulating said filling speed, said cross-section being selected from the group consisting of a flow cross-section and an orifice cross-section.
 18. The apparatus of claim 16, wherein said valve assembly comprises: a return gas path configured in said housing for discharging a return gas that is displaced from said container by liquid product flowing into said container, and a return gas valve disposed on said return gas path, wherein a cross-section or orifice cross-section of said return gas valve is infinitely variable for controlling or regulating said filling speed, said cross-section being selected from the group consisting of a flow cross-section and an orifice cross-section.
 19. The apparatus of claim 16, wherein said apparatus is configured to fill containers that are in a sealed position up against said filling element.
 20. The apparatus of claim 16, wherein said valve assembly comprises a fluid valve having a cross-section that is infinitely variable for controlling or regulating filling speed, wherein said fluid valve is selected from the group consisting of a liquid valve and a gas valve, and wherein said cross-section is selected from the group consisting of a flow cross-section and an orifice cross section.
 21. The apparatus of claim 29, further comprising a device for superimposing an infinitely variable change in flow cross-section or orifice cross-section on an incremental adjustment, said device being selected from the group consisting of a control device and an actuating device.
 22. The apparatus of claim 16, wherein said device comprises a triggerable actuating element, said triggerable actuating element selected from the group consisting of an electrically triggerable actuating element, a hydraulically triggerable actuating element, and a pneumatically triggerable actuating element.
 23. The apparatus of claim 21, wherein said device comprises a triggerable actuating element, said triggerable actuating element being selected from the group consisting of an electrical linear drive, a hydraulic linear drive, a piezoelectric actuator, and a piezoelectric motion element.
 24. The apparatus of claim 21, wherein said device comprises a first actuating element for causing an incremental valve lift and a second actuating element for causing an infinitely variable valve lift that is superimposed on said incremental valve lift.
 25. The apparatus of claim 16, wherein said filling element is configured for open-jet filling of containers.
 26. The apparatus of claim 19, wherein said filling element is configured to form, in a region of said delivery orifice, a seating for a mouth of said container.
 27. The apparatus of claim 16, further comprising a rotor that is rotatable about a vertical machine axis, wherein said filling element is mounted on said rotor.
 28. The apparatus of claim 27, further comprising an electronic controller for controlling or regulating said filling speed as a function of an amount of product that flows into said container during a particular filling phase.
 29. The apparatus of claim 28, wherein said controller is configured for controlling or regulating a filling speed as a function of a desired value associated with a filling curve.
 30. A method of filling containers with a liquid product, said method comprising: during each filling phase, controlling or regulating a filling speed, said filling speed corresponding to an amount of product flowing into a container per unit time, wherein controlling or regulating said filling speed comprises controlling an infinitely variable change of a cross-section of a valve assembly, said cross-section being selected from a group consisting of a flow cross-section and an orifice cross-section.
 31. The method of claim 30, wherein controlling or regulating filling speed comprises changing an infinitely variable cross-section of a fluid valve as a function of an actual value that corresponds to at least one of a current filling speed and an amount of product that has already flowed into said container, said fluid valve being selected from the group consisting of a liquid valve and a return gas valve, and said cross-section being selected from the group consisting of an orifice cross-section and a flow cross-section.
 32. The method of claim 30, wherein controlling or regulating a filling speed comprises controlling and regulating said filling speed as a function of time.
 33. The method of claim 30, wherein controlling or regulating a filling speed comprises controlling and regulating said filling speed as a function of a container-specific filling curve. 